Tandem compound elastic fluid turbine arrangement



Feb. 5, 1946. G,.B. WARREN 2,394,125

TANDEM CQMBQUND ELASTIC FLUID TURBINE ARRANGEMENT Filed Nov. 1, 194:5 2 SheetS- -Sheet 1 .Feb. 5,1946. B'WARREN 2,394,125

TANDEM COMPOUND ELASTIC FLUID TURBINE ARRANGEMENT Filed Nov. 1, 1943 2 Sheets-Shegt 2 Fig.2.

- Invehtor: Glenn 5. Warren,

by A

His Attorney.

Patented Feb. 5, 1946 UNITED. STATE TANDEM COMPOUND ELASTIC FLUID TURBINE ARRANGEMENT Glenn B. Warren, Schenectady, N. Y., assignor to"Genera1'E1ectric Company, a corporation of New York Application November 1, 1943, Serial N0.'508,5B8

1 Claim. (Cl. 253--69) The present inventionrelates to tandem compound elastic fluid turbine arrangements having high pressure and low pressure turbines or turbine parts with a single shaft supported near the ends of the turbine arrangement and at one or more intermediate points. Such arrangements are generally used when it is desired to produce considerable load output of the order of 50,000 kw. or more on a single shaft. Such shaft may be of one piece or in several sections aligned and rigidly fastened together. Difficulties have heretofore been experienced with the alignment of the bearing or bearings for supporting intermediate shaft portions. Another drawback of these arrangements is "the great friction loss incurred in present crossover conduits for conducting elastic fluid discharged from the high pressure part to the low pressure part or parts of such tandem compound steam turbine arrangements. r

The object of my invention is to provide an improved construction of turbine arrangements of the type above specified whereby the aforementioned difficulties are materially reduced.

For a consideration of what I believe to be novel and my invention, attention is directed to the following description and the claim appended thereto in connection with the accompanying drawings,

In the drawings Fig. 1 illustrates a tandem compound turbine arrangement embodying my invention in which the low pressure part is in the form of a single flow turbine, and Fig. 2 is a modification of my invention in which the low pressure part is in the form of a multiple flow, more specifically a triple flow turbine. Figure 3 is a sectional view on 1ine'3-3 of Figure 1.

The arrangement of Fig. 1 comprises a high pressure turbine l and a low pressure turbine II. The highpressure turbine II] has an inlet conduit I2 for conducting elastic fluid to the turbine and valve means I3, I4 for controlling the flow of elastic fluid through the turbine. The valves are not shown in detail because they do not form a particular part of my invention. The turbine has an outer casing I5 and an inner casing I6 suitably supported on the outer casing. The rotor includes a shaft or shaft section H with a plurality of bucket wheels I8 fastened thereto. Elastic fluid is directed to successive wheels by nozzle diaphragms I9 disposed between the wheels and supported on the inner casing I6.

Similarly, the low pressure turbine includes an outer casing 20, a rotor having a shaft or shaft bearing casing 23.

section 2| aligned with the shaft section II and rigidly secured. thereto and carrying a plurality of bucket wheels 22. Fluid discharged from the last bucket wheel I8 of the high pressure part is conducted to the first wheel of the low pressure part I I- by means including a diaphragm or fluid guide and directing device .23. Fluid is conducted from the first bucket stage wheel 22 to the succeeding bucket wheels by means of other suitable fluid guide and directing means or diaphragms 24 disposed between adjacent wheels 22 andsuitably supported onthe casing 20,

Thebearing means for supporting'the single shaft with the sections I7, 2! comprises-the usual bearings 25 and 26 providednear the high PIGS? sure end and low pressure end respectively of the tandem compound turbine arrangement, In addition to the bearings 25, 26 I provide other bearing meansior supporting an intermediate portion. or portions of the single shaft. These other bearing means according to my invention are completely enclosed in the turbine shell or casing and have an outer bearing casing which forms part of a channel for conducting elastic fluid'fromthe high pressure to the low pressure part of the turbine arrangement. In the present instance I have shown. a single bearing 21 for supporting an intermediate portion of the shaft 11, 26 between the high pressure part to and the low pressure part H. The bearing '21 has an "inner casing or bearing member 28 supported on and enclosed within an outer Thelatter @has end lwalls sealed to the respective shaft sections ll, 2I by means of packings 30 and 3| respectively; One end portion of the outer bearing casing 29 has an annular projection 32 forming part of the first stage diaphragm 23 and having a tongue and groove connection with an outer nozzle forming part of such diaphragm. Thus, the outer bearing casing 29 constitutes a means for positioning and supporting the first stage diaphragm or annular fluid directing and guiding means for the low pressure turbine part. portions of the inner and outer bearing casings are sealed together by means including annular flexible sealing rings 33, thus forming a ring chamber between the two bearing casings. This chamber is connected to conduits 34 and 35 through which air or like cooling medium may be circulated through the chamber during operation to maintain the inner bearing casing relatively cool. The hearing as a whole is supported on the turbine casing or shell, in the present instance on a flanged cylindrical extension 36 of End the low pressure casing 20. Diametrically opposite portions of the outer bearing casing 29 havev 7 horizontal projections or arms 31 held in recesses g 38 formed in ,webs 39 of the cylindrical turbine casing extension36. In addition the outer bearing casing 29 is guided on the extension 36 by meansincluding vertical projections or arms 40 on the bearing casing cooperatively associated V 'with corresponding projections 4| on the extension 36 of the turbine casing. Thus the bearing is loosely held and centered on one of the turbine casings or an extension thereof between i successive" turbine stages. The extension36 and the outer casing 29 of the bearing form an annular channel for conducting elastic fluid from the high pressure part In to the low'pr'essure part II; This annular channel produces little friction loss as compared with the usual type of crossover conduit. 7 i V V In the arrangement of Fig. 2 the tandem com-f pound turbine comprises a high pressure part 50 The high pressure part 50 has a shaft section 64' and the low pressure part 52, 53 has a shaft section 55 forming together a single shaftwhich in the present instance is supported by means of four bearings, a bearing 66 near the high pressure end of the arrangement, a bearing 61 near the low pressure end of the arrangement, and

' two bearings 68 and 69 associated with spaced intermediate Portions of the shaft 64, 65. The bearing 68 is located between the outlet of the 1 high pressure part 50 and the inlet of the single flow, low pressure part 52, and the bearingrfia'is located between the single flow, low pressure part '50 and the double flow, low pressure part 53. Each ofthe bearings 68, .69 has inner and outer casingswith the inner casing suitably supported on the corresponding to the high pressure' p'art l0 bf Fig.

l'anda' low pressure part 5| which is of the mul 3 tiple flow, more particularly the triple flow type.

This triple flow, low pressure turbine comprises a single flow part 52 corresponding to the single" flow; low pressure part II of-Fig. land a double flow part 53 arranged in parallel withthe single flowpart52. l

The low pressure parts 52, 53 are arranged in alignment with thehigh pressure part'50, the single flow part 52 being interposed between the high pressure part. 50 and the double flow part 53, the axial direction of fluid flow being the same in athe high pressure part 50, the single fiow part '52, and the outer half of the double flow part 53,

the flow through the inner half of the double flow part beingaxiallyin opposite direction. The

high pressure part 50 has a casing 54 with an inlet 55-and control valve means 56, 51. The

low pressure parts 52,53 have casings 58 and-59 respectively enclosed withina common exhaust hood 6!]. Elastic fluid discharged from the high pressure part is conducted to the low pressure part by .means of a substantially cylindrical extensions! of the high pressure casing-54. This extension conducts fluid from the.last stage of the high pressure'part, directly to the single flow part. 52. An .upper portion ofthe .extension =6! has a circumferentially. extending opening '62 connected :by meansiincluding a crossover conduit 53 .to the .inlet of the double flow. part 53.

The inner wall of vthe crossover conduit 63, is

formed by apart orthe exhaust hood '60.

outer casing and the outer casing in turn supported on the exhaust hood by means including an axially extending web 10 welded or suitably secured to the exhaust hood 60 and the extension BI, and stiffening ribs 7| between the web 10 and the-hood '60. The bearing 68 in this arrangementdoes not'constitute a support for the first stage diaphragm of the single. flow part 52.

What I claim-as new and desir'e to secure by.

Letters-Patent of the United States is: V

In a large capacity tandem compound elastic fluid turbine, a singlecasing containinga high pressure part and a low pressure part, each having a plurality of turbine stages with the entrance to thelow pressure part closely adjacent anddirectly facing the exit from the high pressure part,

a single shaft for both parts, and bearing means.

in the casing including a bearing supporting a shaft portion between the exit of the low pressure part and the inlet of the high pressure part; said bearing having an outer casing within and spaced from the turbine casing and fOlmiIlg therewitha substantially unobstructedannular passage short in length and large in cross-sectional area for conducting elastic fluid from the exit of the high pressure part directly to the .inlet of the low pressure part with a minimum of friction losses. 

